<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<title></title>
		<script>
			function test(){
				alert("你已经成功调用单击鼠标的事件程序！");
			}
		</script>
	</head>
	<body>
		<button id="btn">按钮</button>
		<script>
			var btn = document.getElementById("btn");
			btn.onclick = function(){
				alert("你已经成功调用单击鼠标的事件程序！");
			}
			btn.onmouseover = function(){
				
			}
		</script>
		
		
		<button onclick="test()" onmouseover="" onmousedown="">按钮2</button>
	</body>
</html>
